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* City of London says some bankers could leave London
* Says EU would not allow euro clearing in London
* Fears trade talks on services would be difficult
By Guy Faulconbridge
LONDON, April 20 (Reuters) - A British exit from theEuropean Union would hurt London's status as a global financialcentre because international banks could move away and eurotrading would be hit, the City of London Corporation said onWednesday.
Many financiers say a British exit would sap London of itswealth, hammer sterling, undermine the world's fifth-largesteconomy and prompt some traders to move their business to otherfinancial centres such as New York and Singapore.
The City of London, which runs the only global financialcentre to rival New York, formally backed Britain's EUmembership last month though some financiers opposed what theysaid was a public foray into domestic politics.
"If the UK votes to leave the EU, there would be seriousconsequences for the City of London's role as an internationalfinancial centre," said Mark Boleat, who is the political leaderof the financial district's municipal body.
"We would see UK-based financial institutions lose access tothe single market and some would consider relocating elsewherein the EU - not overnight but over time," Boleat said at adebate hosted by Thomson Reuters in London.
London dominates the $5.3-trillion-a-day global foreignexchange market and is by far the most important financialcentre in the European Union, vying with New York for the titleof the world's financial capital.
"It is also unlikely that the EU would allow euro clearingto continue outside its borders," Boleat said.
Sold sedately for centuries at the Royal Exchange oppositethe Bank of England, foreign exchange is now traded at highspeed among mostly foreign banks such as Citi, DeutscheBank, Barclays, JPMorgan and UBS.
London accounts for 41 percent of global foreign exchangeturnover, more than double the nearest competitor, New York,according to the Bank for International Settlements. London'sclosest European competitors are Switzerland and Paris, whicheach take about 3 percent of global foreign exchange turnover.
Boleat said Lloyds of London, HSBC , JP Morgan, Barclays and Citigroup had cautioned aboutjob losses and possible relocation if Britain opted to leave onJune 23.
While the popular press has cast bankers as the villainsbehind the 2008 financial crisis, the financial services sectormakes up at least a tenth of Britain's $2.9 trillion grossdomestic product.
Boleat said that after a Brexit, Britain would have no sayover EU rules that would apply to institutions seeking tooperate in the bloc and that financial services would be adifficult part of any new trade deal.
"There is no doubt that both the UK and the EU would have aninterest in securing a trade deal as quickly as possible.However this would matter more to the UK than the EU," Boleatsaid.
"Financial and related professional services would need totake their place among all the other sectors to be negotiated,"he added.
Members of Britain's "Out" campaign say such warnings areoverblown and that Britain would prosper if it broke free fromwhat they say is a doomed, German-dominated bloc that punchesway below its weight beside rivals such as Russian PresidentVladimir Putin. (Editing by Stephen Addison)
